#pragma ident "$Id$"

//============================================================================
//
//  This file is part of GPSTk, the GPS Toolkit.
//
//  The GPSTk is free software; you can redistribute it and/or modify
//  it under the terms of the GNU Lesser General Public License as published
//  by the Free Software Foundation; either version 2.1 of the License, or
//  any later version.
//
//  The GPSTk is distributed in the hope that it will be useful,
//  but WITHOUT ANY WARRANTY; without even the implied warranty of
//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//  GNU Lesser General Public License for more details.
//
//  You should have received a copy of the GNU Lesser General Public
//  License along with GPSTk; if not, write to the Free Software Foundation,
//  Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110, USA
//
//  Copyright 2007, The University of Texas at Austin
//
//============================================================================

//
//
#ifndef GPSTK_ENUUTIL_HPP
#define GPSTK_ENUUTIL_HPP

// gpstk
#include "Triple.hpp"
#include "Matrix.hpp"
#include "Vector.hpp"
#include "Xvt.hpp"

namespace gpstk
{
/** @addtogroup geodeticgroup */
//@{

/// A utility for converting from Cartesian in XZY to East-North-Up (ENU)
class ENUUtil
{
public:
    // Constructors
    /**
     * Given a location as a (geodetic) latitude and longitude
     * the constructor creates the appropriate rotation matrix
     * from XYZ to ENU and retains it for later use.
     * @param refGeodeticLatRad geodetic latitude of point of interest (radians)
     * @param refLonRad longitude of point of interest (radians).
     */

    ENUUtil( const double refGeodeticLatRad,
             const double refLonRad);

    // Methods
    /**
     * Convert from a vector in ECEF XYZ to ECEF ENU using the
     * current rotation matrix.
     * @param inV,inVec,in vector of interest in ECEF XYZ.
     * @return Same type as input but with the vector in ECEF ENU
     */
    gpstk::Vector<double> convertToENU( const gpstk::Vector<double>& inV ) const;
    gpstk::Triple         convertToENU( const gpstk::Triple& inVec ) const;
    gpstk::Xvt            convertToENU( const gpstk::Xvt& in ) const;

    /**
     * Update the rotation matrix to the new location without creating
     * a new object
     * @param refGdLatRad geodetic latitude of point of interest (radians)
     * @param refLonRad longitude of point of interest (radians).
     */
    void                  updatePosition( const double refGDLatRad,
                                          const double refLonRad );

    // Utilities
protected:
    void compute( const double refLat,
                  const double refLon);

    Matrix<double> rotMat;
};

//@}

}
#endif
